F-factor

The F-factor, in diagnostic radiology, is the conversion factor between rontgensand rads(or, in more modern units, coulombs/kgto grays). In other words, it converts between the amount of ionization in air (rontgens) and the absorbed dose in tissue (rads). The two determinants are of the F-factor are the effective Zof the material and the type of ionizing radiationbeing considered. Since the effective Z of air and soft tissue is approximately the same, the F-factor is approximately 1 for many x-ray imaging applications. However, bone has an F-factor of up to 4, due to its higher effective Z.

References

Bushberg et al., 2002. The Essential Physics of Medical Imaging. Philadelphia: Lippincott Williams & Wilkins. (p. 55)

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/F-factor Wikipedia article F-factor.